Apollo Economist Warns Diesel Price Rise May Evade Fed Inflation Tracking

If diesel cost increases are being absorbed into non-energy CPI categories, the Federal Reserve's standard inflation metrics may be understating price pressure in the broader economy.

Apollo Global Management chief economist Torsten Slok stated on September 25, 2026, during an appearance on Bloomberg Surveillance, that rising diesel prices present an inflation risk that the Federal Reserve may not be fully accounting for in its policy deliberations. Slok's specific concern, as quoted by Bloomberg, is that diesel cost increases are "entering elsewhere in the CPI basket than in the energy line," meaning the price pressure may be distributed across multiple non-energy categories rather than appearing as a direct energy cost spike.

The Consumer Price Index, published monthly by the Bureau of Labor Statistics, separates energy costs from other goods and services. The Federal Reserve frequently references core CPI, which strips out food and energy prices entirely, as a preferred gauge of underlying inflation. If diesel price increases are flowing into freight, manufacturing, and food distribution costs rather than the headline energy category, they would show up in core CPI rather than the energy subindex, potentially distorting the signal the Fed uses for rate decisions.

Diesel fuel is a primary input cost for the trucking industry, which the American Trucking Associations reports moves approximately 72.5 percent of all freight tonnage in the United States. When diesel prices rise, carriers typically pass those costs forward through fuel surcharges applied to shippers. Shippers, in turn, may incorporate higher transportation costs into the prices of finished goods, which would register as goods inflation in the CPI rather than energy inflation.

Slok did not specify the precise dollar amount of diesel price change underlying his warning. The U.S. Energy Information Administration publishes weekly retail diesel price data by region. As of the most recently available EIA weekly report prior to September 25, 2026, the exact national average retail diesel price and its percentage change over the prior 12 months would be the data point needed to quantify the magnitude of the concern Slok raised. That figure is publicly available in EIA's Weekly Retail Gasoline and Diesel Prices database.

The Federal Open Market Committee, which sets the federal funds rate, next meets in November 2026. Its members receive economic projections and inflation data through the Federal Reserve's Tealbook, which is not publicly released until five years after each meeting. What is publicly available in advance of each meeting includes the Fed's Beige Book, which is published eight times per year and summarizes economic conditions by district. The most recent Beige Book would include anecdotal reporting from businesses on freight and input costs.

Apollo Global Management, where Slok serves as chief economist, manages approximately $650 billion in assets as of its most recent public disclosures. Apollo is a registered investment adviser with the Securities and Exchange Commission, and its regulatory filings are publicly available through the SEC's EDGAR system. Slok's commentary represents his economic analysis and is not a filing or regulatory statement.

Congress has indirect oversight of Federal Reserve policy through the Humphrey-Hawkins reporting requirements, which mandate that the Fed chair testify before the Senate Banking Committee and the House Financial Services Committee twice per year. Fed Chair testimony transcripts and written reports are publicly available through the Federal Reserve's website. The next scheduled Humphrey-Hawkins testimony date has not yet been confirmed for the fall 2026 calendar.

The question of whether the Fed's current inflation measurement framework adequately captures supply-chain-embedded price changes is not new. During the 2021 to 2023 inflation period, multiple economists and Federal Reserve Bank presidents publicly discussed the difficulty of identifying whether inflation was supply-driven or demand-driven in real time, a debate documented in FOMC meeting minutes available through the Federal Reserve's public records archive.

What remains unknown from Slok's Bloomberg statement is the specific magnitude of diesel price increase he is referencing, which CPI subcategories he believes are absorbing the cost pass-through, and whether Apollo has published a formal research note quantifying the effect. A formal research publication from Apollo, an EIA diesel price trend report, and the next BLS CPI release would together provide the data needed to assess the numerical basis for his warning.